Self-propelled armor-piercing shells



Oct. 11, 1966 B. MAILLARD 3,27

SELF-PROPELLED ARMOR-PIERCING SHELLS Filed Nov. 4, 1964 2 SheetsSheet 1 Oct. 11, 1966 B. MAILLARD SELF-PROPELLED ARMOR-PIERCING SHELLS 2 Sheets-Sheet 2 Filed Nov. 4, 1964 United States Patent 3,277,825 SELF-PRUPELLEI) ARMOR-PIERCIN G SHELLS Bernard Maillard, Geneva, Switzerland, assignor to Brevets Aero-Mecaniques S.A., Geneva, Switzerland, a society of Switzerland Filed Nov. 4, 1964, Ser. No. 408,871 Claims priority, application Luxembourg, Nov. 7, 1963, 44,772; Dec. 5, 1963, 44,951 3 Claims. (Cl. 102-49) The present invention relates to self propelled armor piercing shells, that is to say to shells, fired in particular from a semi-automatic or automatic -gun, including an armor piercing core and a propelling charge intended to give said shells, when they are on their trajectory, a supplementary impulse.

The chief object of the present invention is to provide a shell of this type which is well adapted to meet the requirements of practice, in particular concerning their practical range and their armor piercing power.

The invention applies to the case of shells including a base of an external diameter substantially equal to the caliber of the shell, said base carrying an armor piercing core which extends frontwardly from said base and is surrounded by an ogive-shaped envelope or cover fixed to said base.

The present invention consists essentially in housing a propelling charge in the elongated space extending between said core and said cover, said elongated space communicating with at least one propelling nozzle extending toward the rear of the shell and preferably housed in said base.

Preferred embodiments of the present invention will be hereinafter described with reference to the appended drawings, given merely by way of example, and in which:

FIG. 1 is an axial sectional view of a self propelled armor piercing shell made according to a first embodiment of the invention;

FIG. 2 is a cross sectional view on the line II-II of FIG. 1;

FIG. 3 is a view similar to FIG. 1 relating to another embodiment;

FIG. 4 is a cross sectional view on the line IV-IV of FIG. 3;

FIG. 5 shows, in elevational view partly in axial section, a third embodiment of a shell according to the present invention.

The following description refers to self propelled armor piercing shells of small caliber intended to be fired from an automatic gun.

Such a shell includes an armor piercing core 1 made of a high density material (for instance a tungsten steel) carried by a 'base 2 the external diameter D of which is substantially equal to the caliber of the gun from which the shell is to be fired, and therefore of said shell. Advantageously, base 2 is made of a material of lower density than the core, for instance of a light alloy. Said armor piercing core 1, which extends frontwardly of base 2, is secured axially on said base, for instance by being forced in a frusto-conical housing 2 provided at the front of said base 2.

Base 2 carries at least one band 3 intended to cooperate with the rifting of the gun barrel from which the shell is to be fired.

The armor piercing core 1 is surrounded by a cover 4, preferably having a thin wall, forming an ogive at the front and fitting at the rear on base 2 to which it is secured in any suitable manner, for instance by screwing, setting or glueing.

The armor piercing core 1 is preferably made of 21 caliber D substantially smaller than the external diameter D of base 2.

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According to the present invention, the elongated space of relatively great volume existing between core 1 and cover 4 is filled with the charge 5 serving to propel the shell (this charge being cast or sintered for instance), said charge being placed in position before the assembly of cover 4 with base 2, and the elongated space containing propelling charge 5 is in communication with at least one propelling nozzle located at the rear of the shell and preferably arranged in the base 2 thereof, as it will be hereinafter supposed.

Thus it is possible to house, in a self propelled armor piercing shell of a given caliber and of a length compatible with good ballistic characteristics, an amount of propelling charge much greater than that which could be provided in shells of the same type as made up to now.

The shell according to the present invention therefore has greatly increased practical range and perforating power.

According to a first embodiment of the present invention, as illustrated by FIGS. 1 and 3, there is provided a single propelling nozzle 6, coaxial with base 2 and opening toward the rear thereof. Advantageously said nozzle is constituted by a separate piece secured (for instance screwed) in a recess provided for this purpose at the rear of base 2. In this case, said base is provided with passages, for instance channels 7, converging toward the rear and uniformly distributed for placing the elongated space that contains propelling charge 5 into communication with axial nozzle 6.

According to another embodiment of the invention, illustrated by FIG. 5, there is provided a plurality of (for instance four) peripheral nozzles 6 opening into the side wall of base 2. Preferably, as shown, the outlets of said peripheral nozzles 6,, are located ahead of band 3 so that the nozzles are protected against the action of the shell launching gases when said shell is still in the launching gun. Besides, the outlets of nozzles 6 may be further protected by plugs (for instance made of a plastic material), not shown, driven out by the propelling charge 5 when said charge is ignited.

The construction illustrated by FIG. 5 leaves the rear portion of base 2 free from nozzles so that it is possible to house a tracer or incendiary composition therein.

Concerning the ignition of propelling charge 5, it should be pointed out that it must take place as soon as possible after the shell has left the launching gun, that is to say a very short time (averaging some thousandths of a second and preferably not exceeding from six to ten th-ousandths of a second for a caliber of 30 mm.) after the time where the ignition means have been brought into action.

In other words, the means for igniting the propelling charge 5 of the shell must have a very short time of response.

According to a first embodiment of the invention, the igniting means are positioned at the rear of the shell and arranged so that they are brought into play by the gases propelling the shell in the barrel of the gun.

For this purpose, for instance, said means, in the case of a shell provided with an axial nozzle 6 such as illustrated by FIG. 1, may consist of an initiator composition 8 filling nozzle 6 and the passages 7 leading to said nozzle, said initiator composition forming a protective screen between the propelling charge 5 and the gases serving to launch the shell when the latter is still in the barrel of the gun.

It is also possible, according to other embodiments of the invention illustrated by FIGS. 3-4 on the one hand and FIG. 5 on the other hand, to locate the means for igniting the propelling charge 5 at the front of the shell, where said means are brought into action by a phenomenon occurring at the ogive end of cover 4.

In the embodiment illustrated by FIGS. 3 and 4, use is made of the heat resulting from the friction of the front end of cover 4 against air. Transmission of this heat is ensured, through an axial element 8,, of high thermal conductivity, thermally insulated from the remainder of the shell and housed in the nose thereof, to an ignating composition 8 responsive to a temperature for instance approximately 400 C., housed inside propelling charge 5 and in the form of an axial sleeve bearing against the nose of cover 1.

In the embodiment of FIG. 5, use is made of the shock waves starting from the nose of cover 4 and which produce important temperature rises. Said shock waves may be collected for instance in a resonance tube 8 When the propelling charge igniting means are disposed at the front of the shell (FIGS. 3-4 and FIG. the inner wall of propelling charge 5 is provided with ignition transmitting conduit 8 Said conduits are advantageously disposed along the generatrices of said inner wall and lead to axial nozzle 6 (through passages 7) in the case of FlGS. 34 or to the peripheral nozzles 6,, in the case of FIG. 5.

Such ignition conduits permit, on the one hand, of obtaining, as soon as ignition has taken place, a relatively large and constant ignition area, and on the other hand, of ensuring evacuation of the combustion gases from the beginning of the ignition of propelling charge 5. Thus said propelling charge may be chosen of high density and of slow combustion velocity.

On the other hand, it should be pointed out that, when the propelling charge 5 is to be ignited from the front and when the shell is provided with a nozzle 6 opening at the rear of base 2, it will be necessary to protect said propelling charge 5 against the action of the gases which serve to launch the shell in the gun barrel. Such a protection may be ensured, for instance, as shown by FIG. 3, by making use of a plug 8 secured by a slight setting in said plug and which will be driven out by the combustion of propelling charge 5.

The shell may further include, as shown by FIGS. 1 and 2, at the front end thereof with an end piece 9 housed in the nose of cover 4. Advantageously this end piece 9 carries radial partitions 10 fitting against the inner wall of cover 4 and provided, at the level of the front end of core 1 with inclined edges 10 which contribute in centering said core.

In a general manner, while the above description discloses what are deemed to be practical and efficient embodiments of the present invention, said invention is not limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the invention as comprehended within the scope of the appended claims.

What I claim is:

1. A self propelled armor piercing shell which comprises, in combination,

a base the external diameter of which is substantially equal to the caliber of the shell,

an armor piercing core carried by said base at the front thereof,

a shell cover secured to said base surrounding said core and extending fron-twardly there-of to form an ogive,

a propelling charge housed in the space between said core and said cover,

and propelling nozzle means opening toward the rear of the shell and located in said base, said propelling nozzle means being in communication with said propelling charge.

2. A shell according to claim 1 wherein said propelling nozzle means consist of a single axial nozzle housed in said base.

3. A shell according to claim 1 wherein said propelling nozzle means consist of a row of propelling nozzles formed in said base and opening in the side thereof.

References Cited by the Examiner UNITED STATES PATENTS 2,724,334 11/1955 Norton et al. 10252 2,968,244 1/1961 Maas et a1. 1024 9 2,989,922 6/1961 Greenwood et al. 102-49 3,177,809 4/1965 Russell-French 102-49 3,199,406 8/1965 Gould 102-49 FOREIGN PATENTS 516,818 1/1940 Great Britain.

BENJAMIN A. BOROHELT, Primary Examiner.

V. R. PENDEGRASS, Assistant Examiner. 

1. A SELF PROPELLED ARMOR PIERCING SHELL WHICH COMPRISES, IN COMBINATION, A BASE, THE EXTERNAL DIAMETER OF WHICH IS SUBSTANTIALLY EQUALLY TO THE CALIBER OF THE SHELL, AN ARMOR PIERCING CORE CARRIED BY SAID BASE AT THE FRONT THEREOF, A SHELL COVER SECURED TO SAID BASE SURROUNDING SAID CORE AND EXTENDING FRONTWARDLY THEREOF TO FORM AN OGIVE, 